Abstract: Provided is a mold manufacturing method with which the requirement of a wide variety of products in a small lot can be satisfied. A cutting step includes forming, through cutting, mold matching surfaces in respective upper and lower molds and forming, through cutting, cavities C1 and C2 in the respective upper and lower molds with the mold matching surfaces being references.

Abstract: A method for judging the properties of molten cast iron which consists of connecting three sampling vessels with an apparatus for obtaining a cooling curve of molten cast iron, measuring a cementite eutectic temperature (TEC) of cast iron poured to the first sampling vessel to which a chilling agent is contained, measuring a eutectic freezing temperature change of molten cast iron poured to the second sampling vessel being free of any additive, measuring a graphite eutectic temperature (TEG) of molten cast iron poured to the third sampling vessel, and inspecting a relation between the cementite eutectic temperature (TEC) and the graphite eutectic temperature (TEG) within the range of the eutectic freezing temperature change of molten cast iron.